Record Details
Field | Value |
---|---|
Title | Effects of salinity on the tolerance, growth, food conversion and oxygen consumption of kelp greenling (Hexagrammos decagrammus) |
Names |
Zahr, Camille Reda
(creator) Tubb, Richard A. (advisor) |
Date Issued | 1984-11-16 (iso8601) |
Note | Graduation date: 1985 |
Abstract | The osmoregulatory capabilities and tolerance of Kelp greenling, Hexagrammos decagramrnus, were studied in a series of seven salinities ranging from fresh water to concentrated sea water of 50 ppt. Results indicated that they were tolerant over a wide range of salinities but were incapable of surviving below 5 ppt and above 45 ppt. In moderate salinities ranging from 7.5 to 45 ppt, the fish required approximately 48 hours for their plasma osmolarity to stabilize. Kelp greenling were hyperosmotic at 7.5 ppt but at higher salinities of 15 ppt and above, became hyposmotic, capable of maintaining the plasma osmolarity about 360 mOsm/Kg in sea water. Acclimation to low salinity (7.5 ppt) for more than two months had no effect on their survival or tolerance to challenges to sea water. The effects of different salinities (7.5, 15, and 30 ppt) on growth, food conversion and oxygen consumption were studied. Fish reared in 15 ppt had the highest relative growth rate and lowest food conversion. There were no significant differences in relative growth rate and food conversion ratios between fish reared at 7.5 and 30 ppt. Kelp greenling at 7.5 and 30 ppt consumed more oxygen than those at 15 ppt. The metabolic costs of maintaining water balance and ion exchange may account for the increased oxygen consumption. |
Genre | Thesis/Dissertation |
Topic | Hexagrammidae |
Identifier | http://hdl.handle.net/1957/22328 |